Hwo
A deep storm system will move from West Virginia Monday morning across
Pennsylvania to western New York by Tuesday morning. This will result
in a soaking rain for our region during the day Monday with a general
half to three quarters of an inch expected. The rain may mix with
some wet snow over the Southern Tier late Monday night with the
changeover becoming more widespread on Tuesday. Some accumulating
lake snows will then be likely Tuesday night, mainly south of Buffalo
and Watertown.
AFD
The closed low aloft and its associated surface low will become
vertically stacked and slowly weaken while rotating somewhere over
southern Ontario and southeastern Quebec Tuesday through Wednesday.
That said, the region will be in a more showery regime with some dry
periods at times especially for locations outside any influences
from the lakes. Additionally, cold air will filter in across the
region from the west, where enough cold air will be in place to
produce a lake response downwind of the lakes. Temperatures across
the lower terrain may warm up enough to switch precipitation to
rain, whereas temperatures across the higher terrain will remain
cold enough to keep all precipitation in the form of snow. Therefore
for those locations across the higher terrain, accumulating snowfall
is likely, though it is too far out to pinpoint down any exact snow
accumulations this far out.